Ball and socket joint protective cap

ABSTRACT

A ball and socket joint protective cap is provided for covering the pin-shaped partial area ( 7 ) of a completely mounted ball and socket joint. At least two hollow cylindrical sections ( 12, 13 ) of different diameters are arranged adjacent in the axial longitudinal direction of the ball and socket joint protective cap ( 11 ). The section ( 12 ) with the larger diameter is arranged at the end of the ball and socket joint protective cap ( 11 ) that is to be attached to the joint housing ( 1 ). For the better protection of the completely mounted ball and socket joint with the ball and socket joint protective cap ( 11 ) attached, the ball and socket joint protective cap has a transition area ( 16 ) extending essentially at right angles to the axial longitudinal direction of the ball and socket joint protective cap ( 11 ) in the transition of the hollow cylindrical sections ( 12, 13 ), wherein the dimension of the diameter of the smaller hollow cylindrical section ( 13 ) of the ball and socket joint protective cap ( 11 ) is only slightly larger than the dimension of the covered conical receiving section ( 8 ) of the pivot pin ( 3 ) of the ball and socket joint. Displacement of the sealing bellows ( 5 ) of the ball and socket joint in the direction of the arrows P is achieved due to this special design during the attachment of the ball and socket joint protective cap to the pin-shaped partial area of the pivot pin, as a result of which the pressing forces are increased in the area of the contact surface between the sealing bellows ( 5 ) and the pivot pin ( 3 ).

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of and claims the benefit (35 U.S.C. §120 and365(c)) of copending International Application PCT/DE 2003/003010 ofSep. 10, 2003, which designated inter alia the United States and whichclaims the priority of German Application DE 102 42 578.7 of Sep. 11,2002. The entire contents of each application is hereby incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention pertains to a ball and socket joint protective capfor covering the pin-shaped partial area of a completely mounted balland socket joint for the period from the manufacture to the installationof the ball and socket joint, the ball and socket joint being providedwith a joint housing and a pivot pin accommodated pivotably therein.

BACKGROUND OF THE INVENTION

Ball and socket joints in which the ball and socket joint protective capof this type is used usually comprise a joint housing and a pivot pinaccommodated within the joint housing by means of a bearing shell. Thepivot pin comprises a spherical bearing surface as well as a pin-shapedpartial area, which extends at it in the axial longitudinal direction ofthe pivot pin and protrudes from the joint housing in the completelymounted state of the ball and socket joint. A conical receiving sectionfor fixing the ball and socket joint at another component, for example,a chassis-side component of a motor vehicle, as well as a threadedsection, which is usually provided for fixing and is provided withexternal threads, are usually present on this pin-shaped partial area.Another component of such ball and socket joints is a sealing bellows,which seals the gap between the housing and the pivot pin protrudingfrom an opening of the housing. The sealing bellows is usually fixedstatically at the housing and is arranged on the conical receivingsection of the pivot pin displaceably in the axial longitudinaldirection of the pivot pin and extending around same.

Usual ball and socket joint protective caps have at least two adjacentsections of different geometries, the section with the larger externaldimension being attached to the housing of the ball and socket joint tobe protected, adjacent to the edge area of the opening for the pivotpin.

The transition area between the individual sections may have a conicaldesign in order to guarantee a sufficient distance from the componentsof the ball and socket joint that are to be protected. The outer end ofthe ball and socket joint protective cap is closed by a cap-likesection, so that a closed interior space is obtained for the protectionof the pin-side partial area and of the sealing bellows after the balland socket joint protective cap has been attached to the joint housing.

In practice, the above-described ball and socket joint protective capsknown so far have the drawback that moisture and dirt penetrate into theball and socket joint especially during the transportation of the balland socket joints despite the ball and socket joint protective capsattached.

SUMMARY OF THE INVENTION

The object of the present invention is therefore to provide a ball andsocket joint protective cap of the type of this class, which guaranteesreliable protection of both the sealing bellows against the action ofexternal forces and an additional protection of the gap between the pinpart and the housing against dirt.

According to the invention, a ball and socket joint protective cap isprovided for covering the pin-shaped partial area of a completelymounted ball and socket joint, which is provided with a joint housingand a pivot pin accommodated pivotably therein. The protective cap isattached to the pivot pin of the ball and socket joint with at least twosections of different geometries, which are arranged adjacent in theaxial longitudinal direction of the ball and socket joint protectivecap. The section with the larger outer dimension is arranged at the endof the ball and socket joint protective cap, which said end faces thejoint housing. A transition area extends essentially at right angles tothe axial longitudinal direction of the ball and socket joint protectivecap. The transition area is arranged at the transition of the sections.

The displaceable sealing bellows located on the pivot pin is displaceddue to this design embodiment in the direction of the joint housing dueto the transition area extending at right angles to the axiallongitudinal direction when the ball and socket joint protective cap isattached to the pin-shaped partial area of the ball and socket joint;this displacement leads to a deformation of the sealing bellows, as aresult of which the sealing bellows becomes axially pretensioned and, asa result of this, the pressing forces increase as a consequence of theradial pretension of this component at the pivot pins of the ball andsocket joint. This result guarantees an increased sealing action andprevents contaminants of any kind from penetrating into the interior ofthe ball and socket joint.

Moreover, an additional sealing surface is created due to the fact thatthe transition area of the ball and socket joint protective capextending at right angles to the axial direction is in contact with theouter edge of the sealing bellows, so that the outer area of the sealingbellows is also protected from contaminants as long as the ball andsocket joint protective cap is attached to the ball and socket joint ifthe protective cap of the ball and socket joint is at the same time incontact with the housing.

It has proved to be advantageous, in particular, to design the sectionsof the ball and socket joint protective cap as hollow cylindricalsections, where the dimension of the diameter of the smaller hollowcylindrical section of the ball and socket joint protective cap shouldbe only slightly larger than the dimension of the covered, pin-shapedpartial area of the ball and socket joint.

Another embodiment of the present invention can be seen in the fact thatthree hollow cylindrical sections of different diameters are providedover the overall axial length of the ball and socket joint protectivecap, wherein the diameter values of the individual sections decreasefrom the end to be attached to the housing to the opposite free end ofthe ball and socket joint protective cap, and a transition areaextending essentially at right angles to the axial longitudinaldirection of the ball and socket joint protective cap is arranged in thetransition area of the hollow cylindrical sections.

Based on this design, an additional step, which can bring about anadditional sealing action in conjunction with the ball and socket jointto be protected, is thus created at the ball and socket joint protectivecap in addition to the technical teaching described in claim 1. Thishappens due to the fact that the step created additionally is present ata recess usually present at the ball and socket joint in the areabetween the conical receiving section of the pivot pin and the threadedsection adjoining same toward the free end. Two annular sealing surfacesare thus formed between the ball and socket joint protective cap and thepivot pin.

It has proved, moreover, to be advantageous that at least one radiallyinwardly projecting elastic tongue, which may be designed as a tongueextending circularly over the entire inner contour if necessary, isarranged at the inner contour of the hollow cylindrical section locatedat the free end of the ball and socket joint protective cap, which saidfree end faces away from the joint housing. This tongue engages a threadof the threaded section of the pivot pin enclosed by the hollowcylindrical section in question and thus ensures a reliable fixation ofthe ball and socket joint protective cap on the pin-shaped partial areaof the pivot pin, and fixation of the ball and socket joint protectivecap at the housing can thus be dispensed with.

An increase in the elasticity of the circular tongue can be broughtabout as an additional expedient embodiment by the radially inwardlyprojecting elastic tongue having a plurality of slots distributed overthe entire circumference of the tongue.

Corresponding to an advantageous variant, the pulling off of the balland socket joint protective cap is facilitated in that at least oneradially outwardly projecting step, which may extend circularly, isarranged at the outer edge of the hollow cylindrical section located atthe free end of the ball and socket joint protective cap, which saidfree end faces away from the joint housing.

An exemplary embodiment of the subject of the present invention will beexplained in greater detail below on the basis of the drawings attached.The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a conventional ball and socket joint witha ball and socket joint protective cap according to the presentinvention attached to it;

FIG. 2 is a sectional view of the ball and socket joint protective capalone; and

FIG. 3 is a top view of the ball and socket joint protective capcorresponding to arrow B from FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The ball and socket joint shown in FIG. 1 is formed essentially from ajoint housing 1, a bearing shell 2 located in an inner cavity of thejoint housing, a pivot pin 3 accommodated within the bearing shell, aclosing ring 4 as well as a sealing bellows 5. The pivot pin 3 has aball head 6 as well as a pin-shaped partial area 7, wherein thepin-shaped partial area 7 is in turn divided into a conical receivingsection 8 as well as a threaded section 9. After the final mounting ofthe entire ball and socket joint, especially the cavity 10 between thesealing bellows 5 and the pivot pin 3 and the outer side of the sealingbellows 5 as well as the pin-shaped partial area 7 are to be protectedfrom contaminants and damage as a consequence of mechanical loads duringthe transportation. After its manufacture, the ball and socket joint isprovided with a ball and socket joint protective cap 11 for thispurpose. This ball and socket joint protective cap 11 has three hollowcylindrical sections 12, 13 and 14 in the exemplary embodiment beingshown. The hollow cylindrical sections have different diameters, thehollow cylindrical section 12 with the largest diameter facing the jointhousing 1 of the ball and socket joint. The hollow cylindrical section13, which is adjacent to the section 12, has a slightly larger diameterthan the conical receiving section 8 of the pivot pin 3, which saidreceiving section is located inside and is covered by the section 12 ofthe ball and socket joint protective cap 11. A transition area 16extending essentially at right angles to the axial longitudinaldirection of the ball and socket joint protective cap 11 is arranged inthe transition between the hollow cylindrical sections 12 and 13. Thistransition area creates a contact surface 17 on the inner side of theball and socket joint protective cap 11, which said contact surface 17comes into contact with a corresponding contact surface 18 of thesealing bellows 5 when the ball and socket joint protective cap 11 isattached to the joint housing 1 and displaces the sealing bellows 5 inthe direction of the arrows P. i.e., in the direction of the jointhousing 1 on the conical receiving section 8 of the pivot pin 3 becauseof the dimensioning of the lengths of the individual hollow cylindricalsections. Due to the displacement in the direction of the arrows P, theradial pretension is also increased at the contact surface with thepin-shaped area 7 and the sealing action is thus improved because of thedeformation of the sealing bellows at its internal diameter that is incontact with the conical receiving section 8 as well as of the archedarea 19 as a consequence of the axial pretension. A sealing gap, whichprotects the outer side of the sealing bellows 5 from contaminants, iscreated at the same time due to the contact between the contact surface17 and the contact surface 18.

The ball and socket joint protective cap according to the presentinvention is also provided in this exemplary embodiment with atransition area 20 extending essentially at right angles to the axiallongitudinal direction of the ball and socket joint protective cap 11 inthe transition between the hollow cylindrical section 13 and the hollowcylindrical section 14. The transition area 20, which is thus shaped asa step, comes into contact with a recess 21 of the pivot pin 3, which ispresent between the conical receiving section 8 and the threaded section9. The contact in the area of the recess 21 of the pivot pin 3 and theball and socket joint protective cap 11 brings about an additionalsealing gap, by which contaminants are prevented from penetrating intothe cavity 22 between the hollow cylindrical section 13 and the conicalreceiving section 8 of the pivot pin 3. The prerequisite for contactwith the recess 21 is that the diameter of the hollow cylindricalsection 14 at the free end of the ball and socket joint protective capbe selected to be only slightly larger than the external diameter of thethreaded section 9.

Furthermore, FIG. 2 shows that to fix the ball and socket jointprotective cap 11 on the pin-shaped partial area 7 of the pivot pin 3,at least one radially inwardly projecting elastic tongue 24, which isdesigned as a tongue extending circularly along the entire innercontour, is arranged at the inner contour of the hollow cylindricalsection 14 located at the free end of the ball and socket jointprotective cap 11, which said free end faces away from the joint housing3. Corresponding to FIG. 1, this tongue engages a thread of the threadedsection 9 of the pivot pin 3, which said threaded section is enclosed bythe hollow cylindrical section 14 in question and thus ensures thereliable fixation of the ball and socket joint protective cap 11 on thepin-shaped partial area 7 of the pivot pin 3, so that fixation of theball and socket joint protective cap 111 at the joint housing 1 can bedispensed with.

An increase in the elasticity of the circular tongue 24 can be broughtabout in such a way that the elastic tongue 24, which is designed as aninwardly projecting circular tongue, has a plurality of slots 26distributed over the entire circumference of the tongue, as this isclearly apparent from FIG. 3.

Corresponding to the views in FIGS. 2 and 3, pulling off of the ball andsocket joint protective cap from the pin-shaped partial area 7 of theball and socket joint is facilitated in such a way that at least oneradially outwardly projecting step 25, which is designed as a circularslot in the exemplary embodiment, is arranged at the outer edge of thehollow cylindrical section 14 located at the free end of the ball andsocket joint protective cap 11, which said free end faces away from thejoint housing 1.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. A ball and socket joint protective cap for covering a pin-shapedpartial area of a completely mounted ball and socket joint provided witha joint housing and a pivot pin accommodated pivotably therein, theprotective cap comprising: a first cap section; a second cap section,said first and second cap section being attachable to the pivot pin ofthe ball and socket joint, said first cap section having a differentgeometry from said second cap section, said first cap section beingadjacent to said second cap section with respect to an axiallongitudinal direction of the ball and socket joint protective cap witha section having a larger outer dimension being arranged at an end ofthe ball and socket joint protective cap, which end faces the jointhousing; and a transition area extending essentially at right angles tothe axial longitudinal direction of the ball and socket joint protectivecap, said transition area being arranged at a transition of said firstsection and said second sections.
 2. A ball and socket joint protectivecap in accordance with claim 1, wherein the adjacent first section andsecond section are hollow and cylindrical, wherein a dimension of adiameter of a smaller hollow cylindrical section of the ball and socketjoint protective cap is only slightly larger than the dimension of thecovered, pin-shaped partial section of the ball and socket joint.
 3. Aball and socket joint protective cap in accordance with claim 1, furthercomprising another section, said first, second and another section eachbeing a hollow cylindrical section of different relative diameters andtogether extending over an overall axial length of the ball and socketjoint protective cap, wherein the diameter values of the individualsections decrease from the end facing the joint housing to the oppositefree end of the ball and socket joint protective cap, said transitionarea extending essentially at right angles to the axial longitudinaldirection of the ball and socket joint protective cap and arranged atthe transition of the hollow cylindrical sections, wherein the dimensionof the diameter of the respective smaller hollow cylindrical section ofthe ball and socket joint protective cap is only slightly larger thanthe dimension of the section of the pin-shaped partial area of the balland socket joint, said section of the pin-shaped partial area of theball and socket joint being covered by one or more of the hollowcylindrical sections.
 4. A ball and socket joint protective cap inaccordance with claim 3, further comprising at least one radiallyinwardly projecting elastic tongue arranged at an inner contour of ahollow cylindrical section located at the free end of the ball andsocket joint protective cap, said free end facing away from the jointhousing.
 5. A ball and socket joint protective cap in accordance withclaim 4, wherein said radially inwardly projecting elastic tongue isarranged at an inner contour of the hollow cylindrical section and isdesigned as a tongue extending circularly along the entire innercontour.
 6. A ball and socket joint protective cap in accordance withclaim 5, wherein said radially inwardly projecting elastic tongue isarranged at an inner contour of the hollow cylindrical section and has aplurality of slots distributed over an entire circumference of saidtongue.
 7. A ball and socket joint protective cap in accordance withclaim 1, wherein at least one radially outwardly projecting step isarranged at an outer edge of the hollow cylindrical section and islocated at a free end of the ball and socket joint protective cap, saidfree end facing away from the joint housing.
 8. A ball and socket jointprotective cap in accordance with claim 7, wherein a radially outwardlyprojecting step is designed as a circular step.
 9. A ball and socketjoint protective cap and ball and socket joint assembly, comprising: aball and socket joint with a joint housing and a pivot pin accommodatedpivotably therein, said ball and socket joint having an axial length; aprotective cap with a first cap section and a second cap section, saidfirst and second cap sections being attached to said ball and socketjoint, said first cap section having a different geometry and beinglarger than said second cap section, said first cap section beingadjacent to said second cap section with respect to an axiallongitudinal direction of the ball and socket joint, said first capsection having a larger outer dimension and being arranged at an end ofthe ball and socket joint protective cap, which end faces said jointhousing and a transition area extending essentially at right angles tothe axial longitudinal direction of the ball and socket joint protectivecap, said transition area being arranged at a transition of said firstsection and said second section.
 10. An assembly in accordance withclaim 9, wherein said adjacent first section and second section arehollow and cylindrical, wherein a dimension of a diameter of said secondsection is only slightly larger than the dimension of the covered,pin-shaped partial section of the ball and socket joint.
 11. An assemblyin accordance with claim 9, further comprising another section, saidfirst, second and another section each being a hollow cylindricalsection of different relative diameters and together extending over anoverall axial length of the ball and socket joint protective cap,wherein the diameter values of the individual sections decrease from theend facing the joint housing to the opposite free end of the ball andsocket joint protective cap.
 12. An assembly in accordance with claim 9,wherein a dimension of a diameter of a smaller hollow cylindricalsection of said ball and socket joint protective cap is only slightlylarger than the dimension of the section of the pin-shaped partial areaof the ball and socket joint, said section of the pin-shaped partialarea of the ball and socket joint being covered by one or more of thehollow cylindrical sections.
 13. A assembly in accordance with claim 11,further comprising at least one radially inwardly projecting elastictongue arranged at an inner contour of one of said hollow cylindricalsections located at the free end of the ball and socket joint protectivecap, said free end facing away from the joint housing.
 14. A assembly inaccordance with claim 13, wherein said radially inwardly projectingelastic tongue is arranged at an inner contour of the hollow cylindricalsection and is designed as a tongue extending circularly along theentire inner contour.
 15. A assembly in accordance with claim 14,wherein said radially inwardly projecting elastic tongue is arranged atan inner contour of the hollow cylindrical section and has a pluralityof slots distributed over an entire circumference of said tongue.
 16. Aassembly in accordance with claim 9, wherein at least one radiallyoutwardly projecting step is arranged at an outer edge of the hollowcylindrical section and is located at a free end of the ball and socketjoint protective cap, said free end facing away from the joint housing.17. A assembly in accordance with claim 16, wherein a radially outwardlyprojecting step is a circular step.